Belt construction the combination of the belt construction and a pulley and methods of making the same

ABSTRACT

A belt construction having opposed inner and outer surfaces with each surface defining a plurality of longitudinally disposed and alternately spaced apart like projections and grooves that are adapted to mesh with a ribbed surface of a pulley, the depth of the grooves of each of the surfaces of the belt construction being substantially less than the approximately 2.4 mm depth of the grooves of a similar belt construction that is adapted to have one of the opposed surfaces thereof mesh with the ribbed surface of the pulley in the same manner as the first mentioned belt construction, the belt construction having a tension section comprising a cushion section and cord member, the cushion section being initially disposed on only one side of the cord member with the cord member thereafter being embedded therein.

CROSS REFERENCE TO RELATED APPLICATIONS:

This application is a divisional patent application of its parent patentapplication, Ser. No. 096,319 filed Jul. 23, 1993, now U.S. Pat. No.5,334,107, which, in turn, is a divisional patent application of itsparent patent application, Ser. No. 717,223, filed Jun. 18, 1991, nowU.S. Pat. No. 5,273,496.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a new endless power transmission beltconstruction and to a new combination of the belt construction and arotatable pulley means as well as to new methods of making the same.

2. Prior Art Statement

It is known to provide the combination of an endless power transmissionbelt construction having opposed side edge means and having opposedinner surface means and outer surface means with each surface meansdefining a plurality of longitudinally disposed and alternately spacedapart like projections and grooves, the belt construction having acertain thickness between the roots of the grooves in the opposedsurface means thereof, and a rotatable pulley means having an outerperipheral ribbed surface means meshing with a portion of one of theinner surface means and the outer surface means of the belt constructionand defining a plurality of longitudinally disposed and alternatelyspaced apart like projections and grooves that respectively haveportions thereof for serially meshing respectively with cooperatingportions of the grooves and projections of the one surface means of thebelt construction, the depth of the grooves of each of the surface meansof the belt construction being approximately 2.4 mm or greater. Forexample, see the U.S. Pat. No. to Takami et al, 4,773,895.

SUMMARY OF THE INVENTION

It is one feature of this invention to provide a new endless powertransmission belt construction that has a ribbed inner surface means anda ribbed outer surface means that cooperates with outer ribbed surfacemeans of pulley means in a manner to overcome some of the problemsassociated with the prior known belt constructions wherein the depth ofthe grooves of each of the surface means of the belt construction isapproximately 2.4 mm or greater.

In particular, it has been found that such prior known double ribbedbelt constructions that are being made with the standard rib profile ofsingle ribbed belt constructions have increased thickness whichcontributes to a significant reduction in flex life if the pulley meansutilized therewith have the conventional diameters thereof that arenormally used with the single ribbed belt construction.

However, it was found according to the teachings of this invention thatthe rib height can be reduced on both sides of the belt construction andthat the resulting new belt construction can be utilized with pulleymeans with typical diameters and have an increase in the flex lifethereof over the prior known double ribbed belt construction.

For example, one embodiment of this invention provides the combinationof an endless power transmission belt construction having opposed sideedge means and having opposed inner surface means and outer surfacemeans with each surface means defining a plurality of longitudinallydisposed and alternately spaced apart like projections and grooves, thebelt construction having a certain thickness between the roots of thegrooves in the opposed surface means thereof, and a rotatable pulleymeans having an outer peripheral ribbed surface means meshing with aportion of one of the inner surface means and the outer surface means ofthe belt construction and defining a plurality of longitudinallydisposed and alternately spaced apart like projections and grooves thatrespectively have portions thereof for serially meshing respectivelywith cooperating portions of the grooves and projections of the onesurface means of the belt construction, the depth of the grooves of eachof the surface means of the belt construction being substantially lessthan the approximately 2.4 mm depth of the grooves of a similar beltconstruction that is adapted to have one of the opposed surface meansthereof mesh with the ribbed surface means of the pulley means.

Accordingly, it is an object of this invention to provide a newcombination of an endless power transmission belt construction and arotatable pulley means therefor, the combination of this inventionhaving one or more of the novel features of this invention as set forthabove or hereinafter shown or described.

Another object of this invention is to provide a new method of makingsuch a combination, the method of this invention having one or more ofthe novel features of this invention as set forth above or hereinaftershown or described.

Another object of this invention is to provide a new endless powertransmission belt construction having one or more of the novel featuresof this invention as set forth above or hereinafter shown or described.

Another object of this invention is to provide a new method of makingsuch an endless power transmission belt construction, the method of thisinvention having one or more of the novel features of this invention asset forth above or herein, after shown or described.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary isometric view looking toward the front end ofan automobile engine which utilizes a prior known belt construction.

FIG. 2 is a view looking perpendicularly toward the front end of theautomobile engine of FIG. 1.

FIG. 3 is a schematic view illustrating the new belt construction ofthis invention in combination with pulley means arranged in a manner fora particular internal combustion engine.

FIG. 4 is a fragmentary perspective view, partially in cross section,illustrating the new belt construction of this invention.

FIG. 5 is an enlarged fragmentary cross-sectional view illustrating thebelt construction of FIG. 4 engaging the ribbed surface of a pulleymeans in the combination of FIG. 3 to produce the new combination ofthis invention.

FIG. 6 is a fragmentary cross-sectional view schematically illustratinghow the new belt construction of FIG. 4 of this invention is formed on aforming drum means.

FIG. 7 is a view similar to FIG. 4 and illustrates another new beltconstruction of this invention.

FIG. 8 is an enlarged fragmentary cross-sectional view taken on line8--8 of FIG. 7.

FIG. 9 is a view similar to FIG. 4 and illustrates another new belt ofthis invention.

FIG. 10 is an enlarged fragmentary side view of the belt construction ofFIG. 9 and is taken in the direction of the arrows 10--10 of FIG. 9.

FIG. 11 is an enlarged fragmentary cross-sectional view taken on line11--11 of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the various features of this invention are hereinafter illustratedand described as being particularly adapted to provide beltconstructions for use with pulley means of an internal combustionengine, it is to be understood that the various features of thisinvention can be utilized singly or in various combinations thereof toprovide belt constructions for other types of apparatus as desired.

Therefore, this invention is not to be limited to only the embodimentsillustrated in the drawings, because the drawings are merely utilized toillustrate one of the wide variety of uses of this invention.

Referring now to FIGS. 1 and 2, an automobile engine is generallyindicated by the reference numeral 20 and utilizes an endless powertransmission belt construction 21 for driving a plurality of drivenaccessories as hereinafter set forth. A belt tensioner is indicated bythe reference numeral 22 and is utilized to provide a tensioning forceon the belt construction 21 in the manner fully set forth in the U.S.Pat. No. to Henderson, 4,596,538, whereby this U.S. patent is beingincorporated into this disclosure by this reference thereto.

The endless power transmission belt construction 21 is made primarily ofpolymeric material and has a polyester load carrying cord in a mannerconventional in the art, the belt construction 21 having opposed innersurface means 23 and outer surface means 24 with such surface means 23and 24 each being ribbed and thereby having a plurality oflongitudinally disposed and alternately spaced apart like projectionsand grooves disposed substantially parallel and intermediate opposedside edges 25 and 26 of the belt construction 21 in a manner well knownin the art. For example, see the aforementioned U.S. Pat. No. to Takamiet al, 4,773,895, whereby this U.S. patent is also being incorporatedinto this disclosure by this reference thereto.

The belt construction 21 is driven in the direction 21' by a drivingsheave or pulley means 27 which is operatively interconnected to thecrank shaft of the engine 20 in a manner well known in the art. Thedriving sheave 23 drives the belt construction 21 in an endless path andthereby drives a sheave or pulley means 28 of a power steering deviceused in the automobile (not shown) utilizing the engine 20, a sheave orpulley means 29 of an engine water pump, a sheave or pulley means 30 ofan air pump of a type used in an anti-pollution system for the engine20, a sheave or pulley means 31 of an engine electrical alternator 32and a sheave or pulley means 33 of a compressor 34 of an airconditioning system for the automobile utilizing the engine 20.

The sheaves or pulley means 27, 28, 30, 31 and 33 respectively haveribbed outer peripheral surface means 35 against which the inner surfacemeans 23 of the belt construction 21 meshes in its driving relationtherewith, such ribbed surface means 35 defining a plurality oflongitudinally disposed and alternately spaced apart like projectionsand grooves that respectively have portions thereof for serially meshingrespectively with cooperating portions of the grooves and projections ofthe inner surface means 23 of the belt construction 21 in a manner wellknown in the art and hereinafter set forth.

However, it can be seen that the outer surface means 24 of the beltconstruction 21 is disposed against the outer peripheral surface 36 ofthe sheave or pulley means 29 to cause a driving relation therewith andthe outer peripheral surface 36 of the sheave or pulley means 29 can beribbed in the same manner as the surfaces 35 previously described tocooperate with the ribs on the outer surface means 24 of the beltconstruction 21 or can remain smooth and still be driven by the ribbedsurface means 24 of the belt construction 21 engaging against suchsmooth surface 36 also in a manner well known in the art to tend toprevent slippage therebetween.

While FIGS. 1 and 2 represent a prior known arrangement, reference isnow made to FIG. 3 wherein one embodiment of the combination of thisinvention is generally indicated by the reference numeral 40 andcomprises a belt construction 41 of this invention looped around oragainst a crank shaft drive pulley means 42, a tensioner pulley means43, a power steering pulley means 44, an alternator pulley means 45, anair conditioner pulley means 46 and an idler pulley means 47 whereby itcan be seen that the inner surface means 48 of the belt construction 41is in driven or .driving relation with the pulley means 42, 45 and 46while the outer surface means 49 of the belt construction 41 is indriving relationship with the tensioner pulley means 43, the powersteering pulley means 44 and the idler pulley means 47 as illustrated.

As best illustrated in FIGS. 4 and 5, the belt construction 41 of thisinvention has opposed parallel side edge means 50 and 51 and anintermediate tension section 52 comprising a polymeric cushion 53 andcord means 54 whereby the inner surface means 48 is defined by an outercompression section 55 of the belt construction 41 that is secured tothe side 56 of the tension section 52 while the outer surface means 49of the belt construction 41 is defined by an outer compression section57 of the belt construction 41 that is secured to the side 58 of thetension section 52.

While the materials forming the belt construction 41 of this inventioncan comprise any suitable polymeric material, all in the manner wellknown in the art, it is to be understood that the various layers of thebelt construction of this invention can also be provided withreinforcing means therein, such as the fiber means 59 illustrated inFIG. 5 for the inner and outer sections 55 and 57. Such reinforcingmeans can be disposed in the cushion means 53 of the tension section 52with or without having the fiber means 59 in the sections 55 and 57 asdesired.

In one working embodiment of the belt construction 21 of this invention,the cushion means 53 of the tension section 52 can contain about 5 phrof reinforcing fiber material, such as the well known stifflex material,with the cushion means 53 running circumferentially around the beltconstruction while the compression sections 55 and 57 are laidtransversely thereto as it is very difficult to make the cushion means52 transversely laid as it has very little strength in the crossdirection and would stretch easily during building.

In any event, it can be seen that the sections 55 and 57 have thesurfaces 48 and 49 thereof defining a plurality of longitudinallydisposed and alternately spaced apart like projections 60 and grooves61, the grooves 61 each having an arcuate root 62 while each projection60 has a generally truncated configuration defined by a flat apexsurface 63 and a pair of opposed converging side walls 64 and 65 asillustrated.

Thus, it can be seen in FIG. 5 that the belt construction 41 of thisinvention has a total thickness T with the grooves 61 having a pitch P,and a depth of D. The roots 62 of the grooves 61 in the section 55 arespaced from the roots 62 of the grooves 61 in the section 57 by adistance M.

A pulley means is indicated by the reference numeral 70 in FIG. 5 andcan comprise any one of the pulley means 42-47 of the combination 40illustrated in FIG. 3 and has a ribbed outer peripheral surface means 71that defines a plurality of longitudinally disposed and alternatelyspaced apart like projections 73 and grooves 74 that respectively haveportions thereof that serially mesh with the grooves 61 and projections60 of the belt construction 21, the surface means 71 being illustratedin FIG. 5 as meshing with the outer surface means 49 of the beltconstruction 21 but it is to be understood that the same could mesh withthe inner surface means 48 thereof in a like manner.

As previously stated, the pulley means 42-47 of the combination 40 havethe projections 73 and grooves 74 thereof formed for normally meshingwith belt constructions wherein the depth D of the grooves thereof isapproximately 2.4 mm or larger, such as 2.8 mm as disclosed in theaforementioned U.S. patent No. to Takami et al, 4,773,895.

However, as previously stated, it was found according to the teachingsof this invention that the depth D of the grooves 61 of the beltconstruction 41 of this invention can be substantially less than theapproximately 2.4 mm depth of the prior known belt construction andstill function with the projections 73 and grooves 74 of the pulleys42-48 with an extended life of the belt construction over the life of asimilar belt construction that is formed of the same material and hasthe same middle thickness M but with a groove depth D of 2.4 mm orlarger whereby the diameters of the pulley means 42-47 need not bechanged even though the belt construction 41 is exposed to considerableflexing as the belt construction 41 moves through the path defined bythe pulley means 42-47 as illustrated in FIG. 3.

In particular, it was found that the depth D of the belt construction 41can be approximately 2.0 mm while the middle thickness M of the beltconstruction 41 is substantially the same as the middle thickness M ofthe prior known belt constructions wherein the depth D was 2.4 mm orlarger.

For example, in the one working embodiment of the belt construction 41wherein the depth D is approximately 2.0 mm, the middle thickness M isapproximately 2.82 mm while the overall thickness T of the beltconstruction 41 is approximately 6.82 with the pitch P for the grooves61 being approximately 3.56 mm.

In addition, the roots 62 of the grooves 61 are each provided with amaximum radius of approximately 0.3 mm as the minimum radius on the tip75 of each projection 73 on the pulley means 70 is approximately 0.3 mmand thereby insures that the roots 62 of the grooves 61 never touch thetips 75 of the projections 730 of the pulley means 70 so as to reduceany tendency of "rib splitting" and to enhance the transverse rigidityof the belt construction 41. This is accomplished by maximizing theradius of the roots 62 of the grooves 61 in order to keep a maximumthickness between the neutral axis cord and the rib root.

Such one working embodiment of the belt construction 41 of thisinvention is approximately 1702.4 mm in length and approximately 21.34mm wide with six projections 60 on each surface means 48 and 49 thereof.This particular belt construction 41 is utilized in the combination 40of FIG. 3 wherein the effective diameters of the pulley means 42, 47,46, 45, 44 and 43 are respectively and approximately 177.0 mm, 81.5 mm,110.0 mm, 57.0 mm, 154.2 mm and 81.5 mm.

While certain dimensions have been previously set forth in connectionwith one working embodiment of this invention, it is to be understoodthat such dimensions are not to be a limitation on the claimed featuresof this invention as other suitable dimensions can be used, as desired.

The belt construction 41 of this invention can be made by the method andapparatus that is generally indicated by the reference numeral 80 inFIG. 6 wherein a metallic drum 81 is provided and has an outerperipheral surface means 82 against which the inner surface means 48' ofan annular section 55' of polymeric material is disposed in a mannerwell known in the art. Thereafter, a layer of cushion material 53' isdisposed against the material 55' and then the cord means 54' is woundonto the cushion material 53' as illustrated in FIG. 6 and in a mannerwell known in the art. Thereafter, a layer of polymeric material 57' isdisposed on top of the cord means 54'. The layers 55', 53', 54' and 57'are then compressed toward the drum 81 by steam and pressure beingapplied thereto, such as against a flexible membrane 83 disposed aboutthe layer 57' so as to form and cure the resulting belt sleeve in amanner well known in the art of building belt constructions from aplurality of layers that are compressed together onto a building drum.

Thereafter, the belt sleeve is cut into individual belt constructions 41and the surface means 48' and 49' have the grooves 61 and projections 60formed therein by cutting, milling or grinding all in a manner wellknown in the art for providing the ribbed surfaces 48 and 49 asillustrated.

Of course, the layers 55', 53', 54' and 57' could be stacked togetheragainst a drum which has the peripheral surface 82 thereof profiled anda means having the surface likewise profiled could be disposed againstthe surface means 49' or the layer 57' so that the resulting belt sleeveformed on the drum 81 would have ribbed surface means 48 and 49 also ina manner well known in the art.

In any event, it can be seen that by first disposing the cushionmaterial 53' in place and then winding the cord means 54' on top of thesame, in effect, the cushion material 53' is disposed on only one sideof the cord means 54' but that the cord means 54' is subsequently movedinto the cushion material 53' in the manner illustrated in FIGS. 4 and 5during the forming of the belt construction 41.

While the belt construction 41 of this invention has been previouslydescribed as having the projections 60 and grooves 61 beingsubstantially identical on both sides 48 and 49 of the belt construction41, it is to be understood that the same could be dissimilar and stilleach have a depth D that is substantially less than the aforementioned2.4 mm of the prior known belt construction.

In particular, reference is now made to FIGS. 7 and 8 wherein anotherbelt construction of this invention is generally indicated by thereference numeral 41A and parts thereof similar to the belt construction41 previously described are indicated by like reference numeralsfollowed by the reference letter "A".

As illustrated in FIGS. 7 and 8, the surface means 49A of the beltconstruction 41A has the grooves 61A thereof with a depth D smaller thanthe depth D of the grooves 61A in the surface means 48A thereof wherebythe depths D of the grooves 61A in the surface means 48A could be theaforementioned 2.0 mm while the depths D of the grooves 61A in thesurface means 49A would be less than 2.0 mm. Also, it can be seen inFIGS. 7 and 8 that the number of projections 60 that form the surfacemeans 49A is greater than the number of projections 60A that form thesurface means 48A.

It is also to be understood that in order to increase the flexibility ofthe belt constructions of this invention, the same could be cogged onone or both opposed surface means thereof if desired.

For example, reference is now made to FIGS. 9-11 wherein another beltconstruction of this invention is generally indicated by the referencenumeral 41B and parts thereof similar to the belt constructions 41 and41A previously described are indicated by like reference numeralsfollowed by the reference letter "B".

As illustrated in FIGS. 9 and 11, the belt construction 41B issubstantially identical to the belt construction 41A previouslydescribed except that the surface means 49B thereof is provided with aplurality of parallel spaced apart grooves 90 that extend substantiallyperpendicular to the longitudinal axis of the belt construction 41B soas to provide individual cogs 91 in relation to the longitudinal grooves61B. Similarly, the surface means 48B is provided with a plurality ofgrooves 90 that are disposed transverse to the longitudinal axis of thebelt construction 41B so as to form the cogs 91.

If desired, the grooves 90 in the surface means 49B can be the samedepth as the grooves 61B in the surface means 49B and the depth of thegrooves 90 in the surface means 48B can be the same depth as the depthof the grooves 61B in the surface means 48B as illustrated. However, itis to be understood that the depth of the cogging grooves 90 as well asthe spacing therebetween could be different, irregular, etc. rather thanuniform as illustrated. For example, the depths of the grooves 90 andthe spacing thereof could be similar to any of the arrangements as isprovided in the U.S. Pat. No. to Miranti, Jr., 4,938,736, whereby thispatent is being incorporated into this disclosure by this referencethereto.

In any event, it can be seen that in each of the belt constructions 41,41A and 41B of this invention, the depth D of the grooves in both of theopposed surfaces thereof are each substantially less than theapproximately 2.4 mm depth of the grooves of the prior known beltconstructions and it may be that the depths of the grooves of the beltconstructions of this invention can be identical or can be different asdesired.

In addition, one or both opposed surface means of the belt constructionof this invention can be cogged in a uniform or non-uniform manner asdesired.

Thus, it can be seen that this invention not only provides a newcombination of a belt construction and pulley means therefor, but alsothis invention provides a new belt construction and a new method ofmaking the same.

While the forms and methods of this invention now preferred have beenillustrated and described as required by the Patent Statute, it is to beunderstood that other forms and method steps can be utilized and stillfall within the scope of the appended claims wherein each claim setsforth what is believed to be known in each claim prior to this inventionin the portion of each claim that is disposed before the terms "theimprovement" and sets forth what is believed to be new in each claimaccording to this invention in the portion of each claim that isdisposed after the terms "the improvement" whereby it is believed thateach claim sets forth a novel, useful and unobvious invention within thepurview of the Patent Statute.

What is claimed is:
 1. In the combination of an endless powertransmission belt construction having opposed side edge means and havingopposed inner surface means and outer surface means with each saidsurface means defining a plurality of longitudinally disposed andalternately spaced apart like projections and grooves, said beltconstruction having a certain thickness between the roots of saidgrooves in said opposed surface means thereof, and a rotatable pulleymeans having an outer peripheral ribbed surface means meshing with aportion of one of said inner surface means and said outer surface meansof said belt construction and defining a plurality of longitudinallydisposed and alternately spaced apart like projections and grooves thatrespectively have portions thereof for serially meshing respectivelywith cooperating portions of said grooves and projections of said onesurface means of said belt construction, the improvement wherein thedepth of said grooves of each said surface means of said beltconstruction is substantially less than the approximately 2.4 mm depthof the grooves of a similar belt construction that is adapted to haveone of the opposed surface means thereof mesh with said ribbed surfacemeans of said pulley means, said belt construction having a tensionsection comprising a cushion section and cord means, said cushionsection being initially disposed on only one side of said cord meanswith said cord means thereafter being embedded therein.
 2. A combinationas set forth in claim 1 wherein the depth of said grooves in said innersurface means of said belt construction is substantially the same as thedepth of said grooves in said outer surface means of said beltconstruction.
 3. A combination as set forth in claim 2 wherein saiddepth of said grooves of said belt construction is approximately 2.0 mm.4. A combination as set forth in claim 3 wherein said certain thicknessof said belt construction is approximately 2.82 mm.
 5. A combination asset forth in claim 2 wherein the pitch of said grooves in said innersurface means of said belt construction is substantially the same as thepitch of said grooves in said outer surface means of said beltconstruction.
 6. A combination as set forth in claim 5 wherein saidpitch of said grooves of said belt construction is approximately 3.56mm. means thereafter being embedded therein.
 7. A combination as setforth in claim 1 wherein the pitch of said grooves in said inner surfacemeans of said belt construction is different than the pitch of saidgrooves in said outer surface means of said belt construction.
 8. Acombination as set forth in claim 1 wherein at least one of said surfacemeans of said belt construction is cogged.
 9. A combination as set forthin claim 1 wherein the depth of said grooves in said inner surface meansof said belt construction is different than the depth of said grooves insaid outer surface means of said belt construction.
 10. In an endlesspower transmission belt construction having opposed side edge means andhaving opposed inner surface means and outer surface means with eachsaid surface means defining a plurality of longitudinally disposed andalternately spaced apart like projections and grooves, said beltconstruction having a certain thickness between the roots of saidgrooves in said opposed surface means thereof, said belt constructionbeing adapted to have one of said inner surface means and said outersurface means thereof mesh with a ribbed outer peripheral surface meansor a rotatable pulley means that has said ribbed surface means defininga plurality of longitudinally disposed and alternately spaced apart likeprojections and grooves that respectively have portions thereof forserially meshing respectively with cooperating portions of said groovesand projections of said one surface means of said belt construction, theimprovement wherein the depth of said grooves of each said surface meansof said belt construction is substantially less than the approximately2.4 mm depth of the grooves of a similar belt construction that isadapted to have one of the opposed surface means thereof mesh with saidribbed surface means of said pulley means, said belt construction havinga tension section comprising a cushion section and cord means, saidcushion section being initially disposed on only one side of said cordmeans with said cord means thereafter being embedded therein.
 11. A beltconstruction as set forth in claim 10 wherein the depth of said groovesin said inner surface means of said belt construction is substantiallythe same as the depth of said grooves in said outer surface means ofsaid belt construction.
 12. A belt construction as set forth in claim 11wherein said depth of said grooves of said belt construction isapproximately 2.0 mm.
 13. A belt construction as set forth in claim 12wherein said certain thickness of said belt construction isapproximately 2.82 mm.
 14. A belt construction as set forth in claim 11wherein the pitch of said grooves in said inner surface means of saidbelt construction is substantially the same as the pitch of said groovesin said outer surface means of said belt construction.
 15. A beltconstruction as set forth in claim 14 wherein said pitch of said groovesof said belt construction is approximately 3.56 mm.
 16. A beltconstruction as set forth in claim 10 wherein at least one of saidsurface means of said belt construction is cogged.
 17. A beltconstruction as set forth in claim 10 wherein the depth of said groovesin said inner surface means of said belt construction is different thanthe depth of said grooves in said outer surface means of said beltconstruction and/or the pitch of said grooves in said inner surfacemeans of said belt construction is different than the pitch of saidgrooves in said outer surface means of said belt construction.
 18. In amethod of making an endless power transmission belt construction havingopposed side edge means and having opposed inner surface means and outersurface means with each said surface means defining a plurality oflongitudinally disposed and alternately spaced apart like projectionsand grooves, said belt construction having a certain thickness betweenthe roots of said grooves in said opposed surface means thereof, saidbelt construction being adapted to have one of said inner surface meansand said outer surface means thereof mesh with a ribbed outer peripheralsurface means of a rotatable pulley means that has said ribbed surfacemeans defining a plurality of longitudinally disposed and alternatelyspaced apart like projections and grooves that respectively haveportions thereof for serially meshing respectively with cooperatingportions of said grooves and projections of said one surface means ofsaid belt construction, the improvement comprising the steps of formingthe depth of said grooves of each said surface means of said beltconstruction to be substantially less than the approximately 2.4 mmdepth of the grooves of a similar belt construction that is adapted tohave one of the opposed surface means thereof mesh with said ribbedsurface means of said pulley means, forming said belt construction tohave a tension section comprising a cushion section and cord means,initially disposing said cushion section on only one side of said cordmeans, and, thereafter, embedding said cord means in said cushionsection